[PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[Wei Yongjun]

Chunk is marked abandoned if the chunk is expires, and it not be
retransmited even if the peer has no PRSCTP capable, but the peer
will still wait for retransmit it to update CTSN.
This patch disable mark chunk abandoned if peer has no PRSCTP
capable.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 net/sctp/chunk.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 6c85564..0d4832d 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -347,6 +347,9 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
 {
 	struct sctp_datamsg *msg = chunk->msg;
 
+	if (!chunk->asoc->peer.prsctp_capable)
+		return 0;
+
 	if (!msg->can_abandon)
 		return 0;
 
-- 
1.6.5.2

Re: [PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[Vladislav Yasevich]

On 03/02/2011 11:20 PM, Wei Yongjun wrote:
> Chunk is marked abandoned if the chunk is expires, and it not be
> retransmited even if the peer has no PRSCTP capable, but the peer
> will still wait for retransmit it to update CTSN.
> This patch disable mark chunk abandoned if peer has no PRSCTP
> capable.
> 
> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
> ---
>  net/sctp/chunk.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
> index 6c85564..0d4832d 100644
> --- a/net/sctp/chunk.c
> +++ b/net/sctp/chunk.c
> @@ -347,6 +347,9 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
>  {
>  	struct sctp_datamsg *msg = chunk->msg;
>  
> +	if (!chunk->asoc->peer.prsctp_capable)
> +		return 0;
> +
>  	if (!msg->can_abandon)
>  		return 0;
>  

The trouble is that timetolive can be set on a message independent of Partial Reliability.
The difference in behavior is that when PR can't be used, a chunk can only be abandoned
if it has not yet been transmitted.  With PR enabled, the chunk can be abandoned at any time.

So, you can't blindly disallow abandonment. 

-vlad

Re: [PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[Wei Yongjun]

> On 03/02/2011 11:20 PM, Wei Yongjun wrote:
>> Chunk is marked abandoned if the chunk is expires, and it not be
>> retransmited even if the peer has no PRSCTP capable, but the peer
>> will still wait for retransmit it to update CTSN.
>> This patch disable mark chunk abandoned if peer has no PRSCTP
>> capable.
>>
>> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
>> ---
>>  net/sctp/chunk.c |    3 +++
>>  1 files changed, 3 insertions(+), 0 deletions(-)
>>
>> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
>> index 6c85564..0d4832d 100644
>> --- a/net/sctp/chunk.c
>> +++ b/net/sctp/chunk.c
>> @@ -347,6 +347,9 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
>>  {
>>  	struct sctp_datamsg *msg = chunk->msg;
>>  
>> +	if (!chunk->asoc->peer.prsctp_capable)
>> +		return 0;
>> +
>>  	if (!msg->can_abandon)
>>  		return 0;
>>  
> The trouble is that timetolive can be set on a message independent of Partial Reliability.
> The difference in behavior is that when PR can't be used, a chunk can only be abandoned
> if it has not yet been transmitted.  With PR enabled, the chunk can be abandoned at any time.
>
> So, you can't blindly disallow abandonment. 

But, how can we do PR if peer has no PRSCTP capable?
Return error to application in sendmsg()? If so, how we check this if there is no asoc?


> -vlad
> --
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Re: [PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[Vlad Yasevich]

On Fri, 2011-03-04 at 13:10 +0800, Wei Yongjun wrote:
> > On 03/02/2011 11:20 PM, Wei Yongjun wrote:
> >> Chunk is marked abandoned if the chunk is expires, and it not be
> >> retransmited even if the peer has no PRSCTP capable, but the peer
> >> will still wait for retransmit it to update CTSN.
> >> This patch disable mark chunk abandoned if peer has no PRSCTP
> >> capable.
> >>
> >> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
> >> ---
> >>  net/sctp/chunk.c |    3 +++
> >>  1 files changed, 3 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
> >> index 6c85564..0d4832d 100644
> >> --- a/net/sctp/chunk.c
> >> +++ b/net/sctp/chunk.c
> >> @@ -347,6 +347,9 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
> >>  {
> >>  	struct sctp_datamsg *msg = chunk->msg;
> >>  
> >> +	if (!chunk->asoc->peer.prsctp_capable)
> >> +		return 0;
> >> +
> >>  	if (!msg->can_abandon)
> >>  		return 0;
> >>  
> > The trouble is that timetolive can be set on a message independent of Partial Reliability.
> > The difference in behavior is that when PR can't be used, a chunk can only be abandoned
> > if it has not yet been transmitted.  With PR enabled, the chunk can be abandoned at any time.
> >
> > So, you can't blindly disallow abandonment. 
> 
> But, how can we do PR if peer has no PRSCTP capable?

That's already taken care of.  We report the message as unsent.  When
PRSCTP is disabled, you may only abandon messages/chunks that have not
been transmitted (assigned a TSN).

> Return error to application in sendmsg()? If so, how we check this if there is no asoc?

How would you have data without an association?

-vlad

> 
> 
> > -vlad
> > --
> > To unsubscribe from this list: send the line "unsubscribe netdev" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> 

Re: [PATCH] sctp: do not mark chunk abandoned if peer has no PRSCTP capable

[Wei Yongjun]

> On Fri, 2011-03-04 at 13:10 +0800, Wei Yongjun wrote:
>>> On 03/02/2011 11:20 PM, Wei Yongjun wrote:
>>>> Chunk is marked abandoned if the chunk is expires, and it not be
>>>> retransmited even if the peer has no PRSCTP capable, but the peer
>>>> will still wait for retransmit it to update CTSN.
>>>> This patch disable mark chunk abandoned if peer has no PRSCTP
>>>> capable.
>>>>
>>>> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
>>>> ---
>>>>  net/sctp/chunk.c |    3 +++
>>>>  1 files changed, 3 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
>>>> index 6c85564..0d4832d 100644
>>>> --- a/net/sctp/chunk.c
>>>> +++ b/net/sctp/chunk.c
>>>> @@ -347,6 +347,9 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
>>>>  {
>>>>  	struct sctp_datamsg *msg = chunk->msg;
>>>>  
>>>> +	if (!chunk->asoc->peer.prsctp_capable)
>>>> +		return 0;
>>>> +
>>>>  	if (!msg->can_abandon)
>>>>  		return 0;
>>>>  
>>> The trouble is that timetolive can be set on a message independent of Partial Reliability.
>>> The difference in behavior is that when PR can't be used, a chunk can only be abandoned
>>> if it has not yet been transmitted.  With PR enabled, the chunk can be abandoned at any time.
>>>
>>> So, you can't blindly disallow abandonment. 
>> But, how can we do PR if peer has no PRSCTP capable?
> That's already taken care of.  We report the message as unsent.  When
> PRSCTP is disabled, you may only abandon messages/chunks that have not
> been transmitted (assigned a TSN).

I got it, thanks

>> Return error to application in sendmsg()? If so, how we check this if there is no asoc?
> How would you have data without an association?
>
> -vlad
>
>>
>>> -vlad
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>>> the body of a message to majordomo@vger.kernel.org
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>>>
>
>
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